Questions on some diferences with iphone & BB

I have a few questions on the way the Blackberry handles things vs the Iphone..

To start off I was contemplating returning my Storm and getting an Iphone..
This is my first BB (and smart phone).

A few questions I have are:

1) I read that the Iphone does not support multitasking/background programs.
Does this mean if I want to check my mail I have to log out of my AIM or visa versa? Does this also mean because I can not be logged onto facebook, myspace,Twitter,AIM and my email that I will not be able to get real time notifications like I do on the Blackberry?

2) I'm just now learning about push email .. Does iphone support this and if not does this again prevent me from getting real time notifications from my email? What are the benefits of push email?

I have a few questions on the way the Blackberry handles things vs the Iphone..

To start off I was contemplating returning my Storm and getting an Iphone..
This is my first BB (and smart phone).

A few questions I have are:

1) I read that the Iphone does not support multitasking/background programs.
Does this mean if I want to check my mail I have to log out of my AIM or visa versa? Does this also mean because I can not be logged onto facebook, myspace,Twitter,AIM and my email that I will not be able to get real time notifications like I do on the Blackberry?

2) I'm just now learning about push email .. Does iphone support this and if not does this again prevent me from getting real time notifications from my email? What are the benefits of push email?

Any other useful info is appreciated.

I can really only accuratley answer part of your questions the rest is what i think is right so dont kill me if im wrong.

Accurate part- by not being able to multitask it will mean that you will have to close one program to veiw the next say you had a text you needed the date out of on ur bb you could hold the bb button switch between calender and sms to make sure you had it right on iphone you will have to exit the calender and go back to text and then exit text to go back to calender just to check and make sure you got it right(cheesey example but makes the point).

the face book twitter and all that i know nothing about.

96.5% sure stuff (lol) i belive that push e-mail is the ablity to recieve e-mail on multiple accounts at one place quickly...i believe and again not 100% here that on the iphone you will get a message saying you have an e-mail message and then have to log on to retrieve if thats not right roast away but my first section is....hope this is some what helpful

ya as for multitasking, an example is open any app, hit the end key (sometimes the clr key wont close the app) but then go to sms then when your done with that, go back to that app u hit the end key on and it will be just how you left it, same with sms when u go back the text you wrote will still be there.

RIM's BlackBerry uses wireless Mail User Agent devices and a BlackBerry Enterprise Server (BES) attached to a traditional e-mail system. The BES monitors the e-mail server, and when it sees new e-mail for a BlackBerry user, it retrieves (pulls) a copy and then pushes it to the BlackBerry handheld device over the wireless network.

BlackBerry became very popular, in part because it offers remote users "instant" e-mail; new e-mails appear on the device as soon as they arrive, without the need for any user intervention. The handheld becomes a mobile, dynamically updating, copy of the user's mailbox. As a result of the success of BlackBerry, other manufacturers have developed push e-mail systems for other handheld devices, such as Symbian- and Windows Mobile-based mobile phones. However, IMAP synchronization through BlackBerry Internet Service is not two-way.

basically, its "pushes" a copy of your email to your BB as soon as you get it. and it dosent act as a email client (ie. outlook, thunderbird) so if you delete it on your BB you can still get it off of your computers email client (as long as you didnt hit delete on mailbox and handheld on BB. im not sure how iphone handles emails as i have not owned one